ESTRO 2024 - Abstract Book

S4799

Physics - Quality assurance and auditing

ESTRO 2024

3. Determine the Δ shift between the centres of each half slit ( F1 for Col=270º and F2 for Col=90º). 4. Determine the optimal CO parameter as the one minimising the distance between both lines. This value makes the centerline coincident with the collimator rotation axis and should, therefore, also optimize the results for the collimator rotation star shot and with the WL tests.

For each of the CO values tested, a collimator rotation star shot and WL test were performed in order to verify that the optimal value of CO was also minimizing the star shot and WL radius.

Results:

Figure 2 shows the obtained results with the proposed test (left axis) and the corresponding linear fit. The results of WL and the collimator rotation star shot are also presented (see right vertical axis in Figure 2).